package com.ww.java8.collect;

import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

public class HashMapDemo {

    public static void main(String[] args) {
        
        ConcurrentMap<String,String> map = new ConcurrentHashMap<String, String>(2);
        System.out.println(map.size());
    }
}
